A conventional photo-shaping method is disclosed in Japanese Patent Application Laid-Open Publication No. 2002-115004 (patent document 1). In this method, a light beam is irradiated onto a specified position of a powder material layer to sinter (including a case of once melt) a corresponding portion of the powder material layer to form a sintered layer. The sintered layer is then covered with a new powder material layer, and a light beam irradiated onto a specified position thereof to sinter a corresponding portion of the new powder material layer, thereby forming a new sintered layer integrally united with the underlying sintered layer. While repeating this process of forming the sintered layers, the outer face of a formed body obtained by laminating the sintered layers is subject to removal process during repetitive steps of forming the sintered layers.
In this conventional photo-shaping method, as disclosed in patent document 1, on the basis of STL model data obtained from three-dimensional CAD model data of a three-dimensional object to be created, processing paths of light beam irradiating means and removal processing means are calculated for carrying out the light beam irradiation process and removal process by the two means, so that the light beam irradiating means and removal processing means are driven based on the obtained processing path data.
In this processing, the processing path used in the removing process (i.e., second path) to be inserted in laminating the sintered layers to form an object can be obtained by sequentially specifying a processing range in a height (vertical) direction even in the conventional CAD. However, when the number of divisions increases in the height direction, it takes much labor and time, and operator's errors are likely to occur.
For example, in the case of performing the removing process when laminating every 10 layers at laminating pitch of 0.05 mm, if the height of formed body is 100 mm, the number of divisions is 200, and if five types of removing tools are used, the total number of divisions becomes 1000. If the second path is calculated by such number of times in setting and entering the height range, this leads operator's labor to be excessive, and errors are likely to occur. Besides, a program must be generated by arranging such number of second paths in the order of processing, and must be transferred to the removal processing means, and this job also takes much time and labor when manually done.